Geometric considerations relevant to hydrogen depth profiling by reflection elastic recoil detection analysis

This work addresses geometric considerations relevant to the accuracy of de pth profiling by reflection elastic recoil detection analysis, which become s an issue when many samples are compared over time or a single sample is r epeatedly analyzed following a sequence of processing steps. In such cases. accurate and reproducible geometric alignment and incident beam energy cal ibration must be performed over time, and are addressed here. Our analysis and experiments show that geometric deviations in the sample tilt angle and incident particle beam steering, as well as deviations from the sample euc entric position, can result in significant errors in depth profiling. As a result, a recommended degree of accuracy is stated for each of these geomet ric components techniques are presented to attain this accuracy. or better. The most notable of these techniques is a laser alignment of the sample ti lt angle. which has a reproducible accuracy of 0.04 degrees. (C) 2001 Elsev ier Science B.V. All rights reserved.